This does not sound like a PTO problem. If she is helping with school tasks, this is up to the principal to decide if she is allowed to help. If she is not working on PTO related projects don't go looking for trouble.
A question has been asked by several parents at our school about classroom volunteers. We have this woman at our school who was an integral part of the PTO for several years. Last year (her last), she was co-president, yet worked at the school as a SSA. She left the day to day PTO operations to the other co-president. Apparently, there were some problems with her as far as theft is concerned. Her daughter has since moved on to middle school.
She was spotted in the school several days helping out in classrooms. This made several parents uneasy because she really has no business in our school anymore. She has caused trouble in the past and has yet to turn in any school keys that she had (claimed to have lost them).
Question to you is this: Do you feel that it is OK for someone who has no children in the school, and has caused trouble in the past be allowed to volunteer at school?